Mutual Coupling Reduction Between Microstrip Antennas at mm Wave Frequencies Using SIW Technology

The reduction of mutual coupling between microstrip antennas using SIW technology at millimeter wave frequencies is analyzed. To prevent the mutual coupling, a row of metallic cylindrical vias using SIW technology are sandwiched between the microstrip antennas at 30 GHz, they are separated by half of a wavelength. Around 8 dB suppression of mutual coupling is obtained by inserting SIW technology based metallic vias between the antennas. The antenna that has been proposed is designed at 30 GHz with a quarter wave impedance matching technique on a 20 mil thick substrate of 2.2 dielectric constant. Ansoft HFSS 3D EM Software was used to model and simulate the proposed antenna structure. In addition, the inserted metallic cylindrical vias have no measurable influence on the radiation characteristics of the antenna.